Printing telegraph apparatus



April 15, 1941; W. J. ZENNER 223mg@ PRINT ING TELEGRAFH APPARATUS Original Filed Dec. 3l, 1936A INVENTOR WALTER J. ZENNER JM 'I A TORNEY.

`Patented Apr. 15, 1941 UNITED STATES PATNT PRINTING TELEGRAPH ArrAaArUs Walter J. Zenner, Des Plaines, Ill., assigner to Teletype Corporation, Chicago, Ill., a corporation of Delaware 9 Claims.

This invention relates to printing telegraph apparatus, and particularly to selector mechanisms for controlling the operation of such apparatus.

'Ihis application is a division of application Serial No. 118,525, led December 3l, 1936 by W. J. Zenner which matured into U. S. Patent 2,228,716, granted on Jan. 14, 1941.

An object of this invention is to provide a selector mechanism of the assisted armature type in which the energy required to be developed by the selector magnet is minimized.

A feature of the invention is to provide a universally adjustable mounting for the selector magnet of a selector mechanism.

Another feature of the invention is to provide completely resilient interconnection between the armature assisting lever and the selector lever in a selector mechanism.

The invention contemplates numerous other features capable of incorporation into selector mechanisms in various combinations.

For a full and complete understanding of selector mechanisms of the type to which the several features of the invention may be applicable, reference may be had to Patent No. 1,937,376 granted November 28, 1933, to Walter J. Zenner.

Briefly stated, the invention contemplates that the armature of a selector magnet may be detached and dissociated from the armature assisting lever, and may instead be applied to a latch which has a shoulder to engage a lug formed on the armature assisting lever or may be applied directly to a selector lever which is movable under the control of the armature lever.

In an alternative embodiment of the rinvention, the selector magnet armature is xed to the selector lever which the magnet may develop insuiiicient energy to attract, and the movement of which is controlled by the armature assisting lever.

For a complete understanding of the invention, reference may be had to the following detailed description, taken in connection with the accompanying drawing, in which- Fig. 1 is a plan view showing a selector mechanisrn in which the selector ma'gnet controls a latch for the armature assisting lever;

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is Ia fragmentary elevational view of .the

selector mechanism of Fig. 1 as seen from the upper edge thereof;

Fig, 4 is a fragmentary plan View showing a selector mechanism in which periodic movement of the armature assisting lever is not affected by the operation of the magnet armature; and

Fig. 5 is a vertical sectional view taken on the line 5--5 of Fig. 4.

Referring now to the drawing in which identical reference characters designate corresponding parts throughout the several views, and particularly to Figs. l and 2, reference numeral 2| designates a mounting plate for a selector mechanism for printing telegraph apparatus. A selector magnet assembly indicated generally by the reference numeral 22 comprises a bracket 23 to which is secured, by means of screws 24, a magnet core 26. Core 26 has two arms, each of which supports a winding 2T which is adapted to be connected to a telegraph line. At their outer ends the arms of core 26 terminate in pole faces 28.

Bracket 23 supports opposed pivot screws 29, which in turn pivotally support a bell crank lever 3|, one arm of which carries selector magnet armature 32, and the other arm of which terminates in a latching shoulder 33. Magnet bracket 23 has a depending boss 39 which, in addition to mounting the lower pivot screw 29 for the latching bell crank 3|, extends through a close tting aperture mounting plate 2| and establishes a center of rotation for selector magnet bracket 23. The bracket 23 is provided with arcuate apertures 36, the arcs of which have their centers on the axis of boss 3ft, and through which extend clamping screws 3l to threadedly engage mounting plate 2l. At a point remote from xboss 34 bracket 23 threadedly supports the shank of an adjusting screw 38 which is provided with head 39, and, spaced therefrom along the shank, iiange 4|. A stud 42 is rigidly secured to mounting plate 2|, and extends upwardly into the space between head 39 and iiange tl. Screw head 39 may be provided with the usual slot (not shown) for cooperation with a screw driver, and there may be provided in the periphery of the head, sockets 43 into which a pin may be inserted for rotation of screw 33 in the manner in which eapstans are rotated. The sockets permit rotation of screw 33 by suitable implement when the installation of the selector mechanism is such as to prevent access to the slotted head by a screw driver.

It will be apparent that when screw 33 is rotated, it can under-go no axial movement, due to the confining action of head 39 and flange 4| upon stud 42. Since screw 33 threadedly engages bracket 23, the latter must move toward or away from stud l2 as the screw is rotated, and in so moving it pivots upon boss 34 and varies the .air gap between pole faces 23 and arm-ature 32.

An armature assisting lever M pivoted by means of screws 46 on bracket 4l secured to mounting plate 2| is disposed in operative alignment with an armature assisting cam 43 included in a selector cam assembly, indicated generally by the reference numeral 43, mounted on power driven shaft 5| extending through mounting plate gaat 2l. Cam assembly 4S is arranged to `be driven from shaft 5l .through discs 52 xed to shaft 5l, resilient discs 53 in frictional engagement with discs 52, and discs 54 fixed to cam assembly it and in frictional engagement with discs 5S. Discs 52, 53, and 5d constitute friction clutch assemblies. Selector cam assembly 13S includes a stop arm 5S which is arranged to be arrested yand released for rotation alternatively under the control of a stop gate 5l included in a stop gate assembly 53. Stop gate assembly 53 has as its foundation a lplate 59 pivoted below a plate @E by means of pivot screw 52 carried by plate 5l which is secured by screws 53 to posts (not shown) mounted on mounting plate 2l. An `arm ofi mounted on pivot screw E2 above plate di has extending therethrough 4the shank of a knurledheaded screw 66 which threadedly engages stop gate mounting plate 59. Plate 5S may be adjusted rotationally about pivot screw E2 and may be clamped in any desired position of adjustment by drawing plate 5S and arm [it into clamping engagement with plate 6I by means of screw Stop gate 5l is pivotally mounted on post El carried by plate 591, has a portion disposed in Ithe path of stop arm 56, and may be latched in that position by shouldered latch lever Eid. Lever 68 is pivotally mounted on the under side of plate 59 and is urged by spring 9 into latching engagement with stop gate 5l. Latch lever E53 is rocked against the resistance of compression spring G9 to lift its shoulder out of latching engagement with the stop gate by a plunger pin 'H in the operating path of which is disposed one arm of a bell crank l2, the other arm of which engages latch lever E3. A plunger operating screw 'l3 carried by extension l of armae tur-e lever arm @il in alignment with plunger pin ll shifts the pin to rock bell crank "i2, which, in turn, rocks latch lever 68 and eects the release of the stop gate when the armature lever is in its extreme clockwise position. Plunger pin 'll is retracted by spring 59 and permits latch lever ii to latch stop gate 5l when armature assisting lever 44 is in its extreme counterclockwise position.

Armature assisting lever lll is shown in Fig. 1 in its extreme counterclockwise position. In moving into this position, it rocks bell crank 3i into its extreme clockwise position through engagement with yieldable compression spring lli associated with bell crank 3l. Armature is thus brought into engagement with pole face 28. Armature assisting lever lll has a lug 'il so disposed in relation Ito shoulder 33 of lever 3i that when levers M and 3l are in their counterclockwise and clockwise positions respectively, shoulder 33 is in blocking relation to lug l' Cam 43 periodically rocks lever #lll into its counterclockwise position, and if magnet 2l is energized and holds armature 32 in opposition to biasing spring 'I8 of bell crank 3l, shoulder 33 will hold armature assis-ting lever lli in opposition to its biasing spring 19 after cam i3 has rotated suiiiciently to remove an apeX from engagement with lever 44 and to present a nadir portion thereto. If magnet 2 is not energized, spring 'i3 withdraws lever 3l from latching engagement with armature assisting lever fill, and spring 'l rocks lever 44 to its clockwise position when a nadir portion of the cam is presen-ted to lever dll.

A selector lever 8l is pivotally supported by screws 82 carried by a mounting bracket 83 secured to mounting plate 2l. A tension spring 8f has one end connected to selector lever Bl and the other end secured .to extension 8f3 of armature assisting lever arm fl. Extension 86 also carries an abutment screw 8l which is adjustable with respect thereto, and the head of which abuts selector lever E?! intermediate its ends. At its free end, which is the right-hand end as viewed in Fig. l, selector ever Si is provided with spaced depending arms SS, by means of which the setting of selector elements of a sword and T-lever selector assembly is controlled.

The sword and T-lever assembly is designated generally by the reference numeral Si, and comprises a plurality of thin, flat selector fingers, or sword levers S2, and an equal number of T-levers 98 individually aligned with the sword levers 9E. -word levers 92 are individually supported by spacer plates which also separate the T-levers and which are mounted on studs Each of the sword levers S2 has at its lofthand end, as viewed in Fig. 1, a disc-like portion Si which is fitted into a correspondingly shaped aperture in a sword operating bell crank lever plvotally mounted on pivot pin 3S. Each of the bell crank levers 98 is arranged to be rocked counterclockwise by one of a lplurality of projections lil carried by the cam assembly i9 in helical arrangement. Adjacent to the disc- -il/:e portion @l each sword lever 92 is provided with oppositely extending arms ll which terminate in abutments lii.

T-lovers S5 are rotatably mounted upon pivot pin lltl carried by mounting plate 2l and each of the lovers S3 is provided with an arm IGS which terminates a disc-like portion ll. T-levers 9:3 are intended to be articulated, by means of the disclike portions itil, to code bars, code discs, or other permutation code elements (not shown) as disclosed in Patent No. 1,745, '33 granted February fl, w30, to S. Morton et al.

Pivot pin Q9, in addition to supporting sword lever operating bell cranks 93, also pivotally supports a locking bell crank lever E68 which has one varm i519 terminating in a cam follower portion which engages a locking cam lil, included in cam assembly ltl, and has another arm II2 terminating in a locking blade H3 adjacent to which selector lever Si is provided with a locking lug liti.

Selector il is adapted to be rocked, in a manner which will be described later, through an arc sufficient to bring one or the other of its arms into the path of one or the other of abut-..ents lili; oi sword levers Q2 as the sword levers are reciprocated leltwardly by associated bell cranks 93, and such angular movement of selector lever Si is suiicient to bring locking lug lift from one side to the other ci locking blade H3. Continued recip-rocation of a sword lever, after one of its abutment-s E53 has engaged one oi the depending arms 83 of selector lever 8l, causes the sword lever to move angularly about the center of its disc-like portion to bring its free end into engagement with its associated Tlevers 93 at either side of the pivotal mounting ltd thereof. The angular movement of sword levers S2 is limited by stop pins l it carried by mounting plate 2l. Sword lever bell cranks 98 and locking bell crank lod are biased clockwise and counterclockwise respectively, by tension springs (not shown).

The selector mechanism shown in Figs. l and 2 is ada ted to be controlled by permutation code signals comprising marking and spacing impulses in Various combinations received by the selector magnet winding 2l from the telegraph line to which it is connected. When the selector mech- Y anism is not operating and is responding to a stop impulse, which is of marking nature and is manifested by energized condition of selector magnet 21, armature 32 is held to pole face 28, latch lever 3| engages lug 11 of armature assisting lever 44 and holds that lever in its extreme counterclockwise position out of engagement with cam 48, which, in the rest condition, presents a nadir portion to lever 44, and abutment screw 13 is drawn away from plunger pin 1|, which, being retracted, causes stop gate 51 to be latched to hold cam assembly 49 motionless. When a code signal combination is received, the rst impulse thereof is the start impulse which results in deenergization of the selector magnet and permits spring 18 to rotate 1atch lever 3| counterclockwise, thus releasing lever 44 which rocks into engagement with cam 48 and depresses plunger pin 1|, whereby stop gate 5l is released from latch lever 68. Cam assembly 49 rotates through one revolution during the reception of a code combination, and, in rotating, cam 48 rocks armature assisting lever 44 counterclockwise, cam unlocks selector lever 8|, these operations occurring periodically, and cam projections |8| rock sword lever bell cranks 88 counterclockwise successively. All of these operations occur in timed relation to the reception of code signal impulses. If the selector magnet is energized at the instant armature cam 48 actuates armature assisting lever 44 to bring armature 32 into engagement with pole face 28 and lever 3| into latching engagement with lug 11, the armature will be held. and latch lever 3| will hold armature assisting lever 44 in its eXtreme counterclockwise position in opposition to tension spring 11, whereby abutment screw 81 will be drawn away from selector lever 8|. Upon the unlocking of selector lever 8|, tension spring 84 will cause the lever to be rotated to its extreme counterclockwise position, whereby one of the arms 88 will be presented to an abutment |83 of a particular sword lever 92 to effect the setting of the sword lever in accordance with the energized condition of the selector magnet. When the selector magnet is deenergized at a time that armature 34 is brought into engagement with pole face 28 by armature assisting cam 48, the armature will not be held, latch lever 3| will not hol-d lever 44, which will return to its extreme clockwise position, and the selector lever, when unlocked, will be positioned in accordance with the deenergized condition of the selector magnet.

A code signal combintion concludes with a stop impulse which is represented by the energized condition of the selector magnet. The armature is thus held, and armature assisting lever 44 is retained in its extreme counterclockwise position by latch lever 3|, whereby plunger pin 68 is permitted to be retracted by spring 69, and stop gate 51 is locked. It follows from this that cam assembly 49 is arrested at the conclusion of one revolution and, with a nadir portion presented to latched lever 44, awaits release by the start impulse of the next code signal combination.

The selector mechanism hereinbefore described has the advantageous feature that` winding 21 is required to carry only sufficient energizing current to cause armature 32 to be held in opposition to tension spring 18. None of the stored energy of armature assisting lever restoration spring 19 is operative upon armature 32, but

is instead resisted by latching shoulder 33 which has positive blocking relation to latching lug 11 until the selector magnet releases its armature. The use of low transmitting potentials is thus made possible.

Another embodiment of the invention, in which a different relationship between armature assisting lever, selector lever, and magnet armature exists, is shown in Figs. 4 and 5. Referring now to those figures, it will be noted that a selector mounting plate |2| supports a selector magnet assembly |22 and brackets |23 and |24 on which selector lever |28 and armature assisting lever |21 are respectively pivotally mounted by means of pivot screws B28 and |29, respectively. Armature assisting lever |21 is urged into extreme clockwise position by tension spring |3| and is periodically rocked counterclockwise by armature assisting cam .|32 included in selector cam assembly |33 carried by powerdriven shaft |34. The armature of the selector magnet is designtaed |38 and is mounted directly on selector lever |28, which has, at its free end, locking lug |31 similar to that employed on selector lever 8| (Fig. l) with which there cooperates locking bell crank lever |38 which is biased counterclockwise by spring |35, and is periodically rocked by cam |48. Since selector lever |26 carries the selector magnet armature |38, the tripping of the stop gate for the selector cam assembly |33 in response t0 a start impulse must be under the control of that lever. Accordingly, lever |28 is provided with an arm |34 having abutment screw |4| in operative alignment with stop gate latch tripping plunger pin |42 of adjustable stop gate assembly |43, a fragment only of which is shown in Fig. 4, but which may be similar to the stop gate mechanism shown in Figs. 1 and 2.

The interconnection between selector lever |28 and armature assisting lever |21 is shown in detail in Fig. 5 by reference to which it will be observed that selector lever |28 is provided with spaced depending arms |44 in alignment with which are depending. arms |48 of armature assisting lever |21 spaced apart a greater distance than are the arms |44. The arms l41 of selec- `tor lever |26 are apertured to receive shouldered pins |41, which are urged in opposite directions by compression spring |48 to force their outer ends into abutting relation with the inner surfaces of arms |48. With the arrangement shown in Figs. 4 and 5, selector lever |28 tends to be centered with respect to armature assisting lever |21, and if the latter is moved angularly, an unbalance is created in the combination of pins |41 and spring |48 which causes the selector lever |26 to be moved in a direction to eliminate the unbalance when it is unlocked by locking bell crank |38. It will be observed that the interconnection between armature assisting lever |21 and selector lever |26 is resilient or permissive in both directions, as contrasted with the interconnection shown in Figs. 1 and 2, comprising a tension spring and an abutment screw, the combination of which affords a permissive or resilient interconnection in one direction, and a positive interconnection in the other direction.

In the operation of a selector mechanism, as disclosed in Fig. 4, it will be presumed that the energizing current of the selector magnet produces enough magnetic attraction to hold selector lever |26 in opposition to a condition of unbalance in the spring interconnection between selector lever and the armature assisting lever,

but which is insuflicient to attract the selector lever from its extreme clockwise to extreme counterclockwise position. Due to the periodic rocking of armature assisting lever |21 counterclockwise by cam |32, an unbalance, tending to rotate selector lever |26 counterclockwise, will be generated in the interconnecting pins HiT and spring |158, and when locking bell crank |38 is actuated by cam Mtl to unlock selector lever |28, the latter will be rotated to bring armature |36 into engagement with the pole face of the selector magnet |22. If the magnet is then energized, the selector lever |26 Will be held in its extreme counterclockwise position after the armature assisting lever EN has returned to its extreme clockwise position due to escapement of its cam follower portion from an apex of cam |32, and a selective condition corresponding to a marking signal is thus established, whereupon locking bell crank cam ift@ permits looking bell crank |38 to lock lever S26.

If instead of being energized at the time the armature assisting lever |21 is rotated counterclockwise, the selector magnet should be deenergized, in response to a spacing signal, the selector lever |25 will not be held and will return to its extreme clockwise position when the armature assisting lever returns to its extreme clockwise position, whereupon the selector lever may be locked in that position, which corresponds to a spacing signal condition of the selector magnet.

With the arrangement shown in Figs. 4 and 5J the selector magnet armature is not associated with the armature assisting lever, but is associated with the selector lever. The selector magnet is not called upon to actuate selector lever |26, no1' to hold it in opposition to the relatively strong restoring spring ISI, but is only required to hold it in opposition to a relatively weak unbalance in the centering spring mechanism when the armature lever returns to its extreme clockwise position. The restoring spring for the armature assisting lever may thus be as heavy as desired. Furthermore, the armature assisting lever is never held out of engagement with the armature cam, as it may be in the structure shown in Fig. 1, by latch lever 3|, but is instead continuously responsive in its movements to the contour of the armature cam.

Although particular embodiments of theinvention have been shown and described herein, it is to be understood that the invention is not to be interpreted as being limited to the specific details shown and described, but is capable of modification and rearrangement within the scope or the appended claims.

What is claimed is:

l.. Inaselectormechanism, a group of selectors, an electroinagnet, an armature for said electromagnet, an element through which said armature is moved toward said electromagnet periodically, and means operated by the electromagnet for holding or releasing said element, a selector lever presentable in either of two positions according to whether said element is held or released, and means for positioning said selectors according to the successive positions of said selector lever.

2. In a selector mechanism, an electromagnet, an armature therefor, an element to be actuated periodically having a portion to control said armature and another portion to be controlled by said armature, and means for effecting the periodic operation of said element.

3. In a selector mechanism, an electromagnet, an armature therefor, said electromagnet adapted to exert a predetermined attractive force upon the armature when energized, a periodically movable element, a cam for eiecting periodic movenent of the element, a spring cooperatinor with said element to urge it into engagement with said cam, said spring exerting a materially greater force than the attractive force of said magnet, and means controlled by said magnet for withholding said element from engagement with the cam in opposition to said spring.

4. In combination, an electromagnet, an armature therefor, a power driven cam, an armature controlling member actuated periodically by said cam, a biasing spring or establishing cooperation between said cam and said member, and means associated with said armature for holding said out of cooperation with said cam without opposing said biasing spring to the attractive force of said electromagnet.

5. In a selector mechanism, an electromagnet, an armature therefor, a selection controlling lever, a power driven cam for periodically rocking said lever, a spring for urging the lever into contact with said cam, means associated with said lever for bringing said armature into engagement with said electromagnet, and means effective upon energization of the electromagnet for holding the lever out of Contact with said cam .vhereby the attracted armature is independent of the action of said biasing spring.

6. In an electro-responsive device, an electromagnet, a power driven cam, a pivoted lever having a portion engageable with said cam, a pivoted latch having a portion to receive movement from said lever and a portion to latch said lever against movement, and an armature for said electromagnet carried by said latch.

7. In an electroresponsive device, an electromagnet, a power driven cam, a pivoted lever having a portion engageable with said cam, a pvoted latch, a yieldable element associated with said latch and engageable by said lever for effecting pivotal movement of said latch, a projection carried by said lever to be engaged by said latch for holding said lever out of engagement with said cam, and an armature for said electromagnet carried by said latch for controlling the latch.

8. In an electroresponsive device, an electromagnet, an armature therefor, a latch lever by which said armature is supported, a leaf spring carried by the armature supporting arm of said iatch lever, a power driven cam, a pivoted lever having a portion engageable with said cam and another portion engageable with said leaf spring for moving said armature into engagement with said electromagnet, a projection carried by said pivoted lever to be engaged by said latch ior holding said pivoted lever out of engagement with said cam, and means effective upon the release of said armature by said electromagnet for restoring said pivcted lever to engagement with said cam.

9. In combination, an electromagnet, a pivoted lever, an armature for said electromagnet carried by said lever, a power driven cam, an armature controlling lever actuated periodically by said cam, a biasing spring for establishing cooperation between said armature controlling lever and said cam, and means carried by said pivoted lever and engagea-ble with said armature controlling lever for rendering mutually independent the force exerted by said electromagnet upon its armature and the force exerted by said biasing spring upon said armature controlling lever.

WALTER J. ZENNER. 

